Enlightenment started as a project to build a Window Manager for X11. That was way back in 1996. It has grown much since. It still produces this Window Manager, but it has evolved to also cover Mobile, Wearable and TV UI needs for projects such as Tizen as well as traditional the “desktop” UI. In the process of developing a Window Manager, A set of libraries were developed in order to achieve that goal. These libraries are known collectively as EFL. They cover a range of functionality from main-loop, to graphics, scene graphs, networking, widgets, data storage, IPC and much more.